FIG. 7 is a schematic cross-sectional view of a basic structure of an organic light-emitting diode (OLED) 28 as comprised in the art. The OLED 28 comprises a substrate 29 through which light can be emitted during operation, as indicated by an arrow 30. The inside of the OLED 28 is encapsulated by a so-termed hermetic cover 31. The OLED 28 further comprises a cathode connector 32 which extends inside the cover 31 adjacent to the cover 31, wherein the extension into the inside (planar structure) of the OLED 28 will hereinafter be termed cathode layer 32a. The OLED 28 further comprises an anode connector 33 which extends inside the cover 31 adjacent to the substrate 29. The structure of the OLED 28 also comprises a stack of organic layers 34 (including, for example, organic layers for light generation, charge generation layers, buffer layers, etc. but not limited to these types of layers), the present version of which shows three layers. This stack of layers 34 is responsible for generating the light to be emitted when powered by an electric signal of suitable polarity and strength, e.g. a direct current (DC) signal applied between the anode connector 33 and the cathode connector 32. The anode connector 33 and the cathode connector 32 realize a terminal structure of the OLED 28. A reference potential is typically provided via the cathode connector 32. The extension of the anode connector 33 into the inside (planar structure) of the OLED 28, hereinafter termed anode layer 33a, adjacent to the substrate 29 is also termed top electrode and may be made of a transparent conduction material, e.g. ITO (Indium Tin Oxide) which is known to have a sheet resistance. Because of the large two-dimensional planar structure or area (e.g. 0.15 m·0.15 m) of the OLED 28 and its sandwich-like design, it already intrinsically comprises a capacitor having a relatively high capacitive value per unit of area or length.
One of the problems of such prior-art OLEDs 28 is related to the sheet resistance created by the anode layer 33a (also termed top electrode). The sheet resistance is responsible for brightness non-homogeneity problems known in the art. Typically, such an OLED 28 shows a gradient in its brightness distribution. The brightness of the emitted light typically drops from the corner or edge region towards the center region of the planar light-emitting surface of the OLED 28.